1. FIELD OF THE INVENTION
The field of the invention is modifications made to the standard available residential and comemrcial toilets of the type having a water holding tank and a bowl wherein means are provided to effect a partial flush of liquid wastes in the bowl in addition to the usual full flush.
2. DESCRIPTION OF THE RELATED ART
Toilets that are commonly in use consist of two main parts, the upper part which holds water, usually called the tank section, and the lower part comprising primarily a bowl with a volume of water which is designed to receive human waste products, commonly called the toilet bowl. Once the waste products have been deposited in the bowl, they are removed by releasing the water held in the upper water holding tank into the bowl which, through a specially designed siphon system, removes the waste products to a collection system, such as a septic tank or sewer system, and then refills the bowl so that there is left standing a volume of water. Wastes comprises both solid and liquid wastes and presently, in toilet systems now available, one flush is utilized to carry away both the solid and the liquid wastes, even for the occasions when there are only liquid wastes in the toilet bowl. In the presently available standard toilets, a full complete flush is effected with each flush and the total contents of the water holding tank drained into the bowl and then out into the sewer system.
In the standard toilets, the water tank holds water up to a level which is determined by a float activated valve which allows water to enter the tank to a predetermined level, and when that level is reached, the valve shuts down. In the base of the tank is located a valve seat with a main valve, often called "flapper valve", operating in and out of that valve seat. The valve seat surrounds a water discharge port comprising a pipe opening and associated pipe which runs from the water holding tank to the toilet bowl and which permits the held water to enter the toilet bowl. Located proximate the valve seat is an upright pipe, called the overflow pipe which permits excess water in the tank whose level is above the top of the overflow pipe to enter the overflow pipe, flow down through the overflow pipe and into the toilet bowl. The purpose of the overflow pipe is to prevent water from escaping out of the top of the tank in the event that the water filling valve should malfunction causing the tank to otherwise overflow.
In the commonly available standard equipped toilets, the main valve which operates in and out of the valve seat is composed of soft pliable rubber and is buoyant in water. Presently, the main valve in most toilets is somewhat ball-shaped or hemispheric, having a surrounding overlapping flange on one side of the ball at about its equator, with the flange being somewhat oval shaped with an extended portion of the flange continuing over to engage a fixture attached to the overflow pipe. With the main valve in a closed position, the flange is generally in a horizontal position. This extending portion of the flange generally encircles an outstanding pin attached to the fixture to provide a pivotal means by which the main valve may pivot out of its position on the valve seat. Attached to the flange opposite the point of pivoting is an upright protruding eyelet which is adapted to be tied to a cord, string, or a hook attached to a chain, the other end of the cord, string, or chain attached to a lever arm of a flush handle, the flush handle itself operating through an opening to be situated outside the tank. When the exteriorly located flush handle is depressed, the lever arm interiorly to the tank rises, pulling upon the eyelet and pivoting upward the main valve off the valve seat and thus opening the main valve. When the main valve has pivoted sufficiently upward so that a certain distance exists between the main valve and the valve seat, water pressure pushing down on the main valve plus the suction effect of the water rushing between the main valve and the valve seat is exceeded by the buoyancy of the main valve and the main valve becomes buoyant and flotas to a position where the flange appears to be pointing upward. The suction pressure caused by the water rushing between the main valve and the valve seat and the downward pressure of the water upon the main valve is such as to attempt to pull the main valve back into position seated upon the valve seat and closing off the flow of water. During the flushing of the toilet, the main valve is raised to a position where it becomes buoyant (and rises or floats to its highest pivotal position) and then all the water in the water holding tank rushes through the opening in the center of the valve seat. Buoyant and buoyancy is defined as the tendency of an object to rise in a liquid.
The water proceeds out the water discharge port, down the pipe connecting the water tank to the toilet bowl, and into the toilet bowl. As the water level in the tank drops to the main valve, the main valve begins to float at the water level and then when the water is nearly exhausted, the main valve, floating now on the descending water level, seats itself again upon the valve seat. Water entering the tank through the float activated valve then covers the main valve and holds it down.
In older toilets, the main valve comprises primarily a ball which has connected to it an outwardly and upwardly protruding elongated rod. The ball is kept in position over the valve seat by passing the rod through a positioning sleeve situated directly over the valve seat. At the end of the rod opposite the ball is an eyelet to which is attached the rope or chain from the flushing handle lever. This older style of main valve operates similarly as does the currently popular pivotable main valve detailed above.
With the efforts which have been popularized recently to save water, a number of inventions have been made to save water in the toilets commonly found in residences. Such efforts have included using smaller sized water holding tanks than used theretofore, and/or redesigning the siphon system of the bowl which carries off the waste products to operate with less water. In addition, since one of the waste products is liquid waste, particularly urine, efforts have also been directed at effecting a partial flush where only a portion of the water stored in the tank is permitted to enter the bowl to carry off the liquid wastes.
In regard to the partial flush, a number of patents have been issued recently disclosing devices adapted to allow a measured amount of water from the water holding tank to enter the bowl. For example, Clary, in U.S. Pat. No. 3,894,299, discloses a dual flush system wherein a spring loaded valve is inserted into the tank overflow pipe whereby the valve allows water from the tank to flow into a submerged opening in the overflow pipe until the level of water in the tank reaches that opening.
Claywel, Johnson, Bell, and Marcum in U.S. Pat. Nos. 4,195,373, 3,903,551, 4,353,138, and 2,754,521 respectively, have disclosed partial flush systems utilizing two separate main valve systems, both of which lead to the bowl, one valve system adapted for tha partial flush and the other valve system adapted for the full flush.
Finally, Deniz, in U.S. Pat. No. 3,151,337 discloses a unique dual flush system where two valves are configured into a serial type arrangement whereby the partial flush procedure allows a top valve to pass water through the interior of the main valve.
All of the prior art known to the inventor and as stated above, involves rather complicated mechanical devices which change substantially the inner working parts of the toilet tank, and are quite expensive and complicated to manufacture, and thus not only expensive for the customer, but require substantial labor in removing the present working parts located in the tank and replacing them with the device shown in each of the patents.
It is apparent that it would be useful to provide a mechanism which effects either a partial flush or a full flush but, which requires minimun interchange of working parts of the toilet and which does not require modification of the water holding tank.
Accordingly, there is an advantage of providing an improved dual system flush toilet wherein the majority of the inner working parts of a standard commercially available toilet system are not replaced, but the existing main valve and other parts directly associated with draining the water from the tank into the bowl are.